1. Field of Art
The present invention relates to a washer-dehydrator with a weight detector for automatically detecting the state or progress of dehydration in a rotating tub on the basis of the change of weight load of the tub during dehydration.
2. The Prior Art
In prior art dehydrators such as the dehydration mechanisms of dehydrators or dehydrators incorporated in dual-tub washing machines, a state detector is used to detect the progress of dehydration, e.g., the end of dehydration. Conventional detectors of this type include an optical sensor for detecting the presence of water drained off during dehydration or a pressure sensor for detecting the impulsive pressure of water splashed from a dehydrating tub during dehydration.
In the case of the optical sensor, the detection accuracy is lowered due to problems such as the soiling of an overflow and the change of the quantity of light from light emitting elements. Also, the measured value varies with the state of water flow, leading to false detection of the end of dehydration.
As for the pressure sensor, the probability of the pressure sensor getting hit by water is very low, thereby causing wrong end detection. Thus, in either case, the detection of the state of the dehydration process lacks reliability.